Various embodiments are based on an apparatus for controlling at least one electrical load.
FIG. 10 shows a conventional installation of loads, in this case electronic control gear for light-emitting means in accordance with the prior art. The electronic control gear are connected to a power supply (N, PE) and are switched on and off via a communications interface (DA). A conventional protocol in this sector is the DALI (Digital Addressable Lighting Interface) protocol. A preferred functionality of the communications interface in relatively small installations is the so-called touch-dim function, which is also controlled by many devices with a DALI interface. A pushbutton is used for this purpose. If the pushbutton is depressed for only a short period of time, the control gear switches the one or more light-emitting means on or off. If the pushbutton is depressed for a relatively long period of time when the light-emitting means are switched on, the light-emitting means are faded up or down. In the case of both a short depression and a relatively long depression of the pushbutton, the function which is respectively complementary to the preceding function is implemented. If the light-emitting means are in operation, they are switched off by a short depression of the pushbutton. If they are switched off, they are switched on by a short depression of the pushbutton and so on. If the light-emitting means are switched on and the pushbutton is depressed for a relatively long period of time, the light-emitting means are faded down. In the case of the next relatively long depression of the pushbutton they are faded up again. The present dimming position can be stored in the device by a “double click”, i.e. two depressions of the pushbutton in quick succession.
The switching-on and switching-off operations can take place at any desired point in time, as can other DALI/touch-dim commands, which means that the electronic control gear need to be constantly communications-ready. The electronic control gear therefore need to have a constant supply of power. This applies in particular also when the light-emitting means of an electronic control gear has been switched off by a DALI/touch-dim command and is in the standby mode.
The above described permanent power supply to electronic control gear results in a high level of undesired power consumption in the standby mode, in particular in the case of large lighting installations.
Relatively large lighting installations are isolated from the power supply system manually or via timer switches in order to reduce the power consumption in the standby mode when it is ensured that they are not required (for example at night). During conventional use times of the installation, however, all of the parts of the installation are supplied with power from the power supply system. Unused parts of the installation are then in the standby operating mode and thus cause an undesirable additional power consumption.
Isolating the lighting installation from the power supply system manually or in a controlled manner via timer switches, as has previously been the practice, in order to save energy also has the disadvantage that the lighting installation can only be activated by additional working steps, if said lighting installation is required during this time as an exception.